.header-logo {
  position: relative;
  margin: 0 0 0 100px;
}
/* 设置a标签的样式 */
.logo {
  display: block;
  width: 55px;
  height: 55px;
  overflow: hidden;
  background-color: #ff6700;
  text-align: left;
  text-indent: -9999em;
}
.logo div div {
  position: absolute;
  top: 0;
  left: 0;
}
.logo div .a1 {
  width: 55px;
  height: 55px;
  /* 设置过渡 */
  transition: all 0.3s;
  /* 背景图片 */
  background: url(../images/mi-logo.png) no-repeat center center;
  /* 透明度 */
  opacity: 1;
  transform: translateX(0);
}
.logo div .a2 {
  width: 55px;
  height: 55px;
  transition: all 0.3s;
  background: url(../images/mi-home.png) no-repeat center center;
  transform: translateX(0);
  opacity: 0;
}
.logo:hover .a1 {
  opacity: 0;
  transform: translateX(55px);
}
.logo:hover .a2 {
  opacity: 1;
  transform: translateX(-55px);
}
